Apparatus and method for installation of pipe liner

ABSTRACT

An apparatus and method for lining sewer pipes that utilize an adjustable form configured to conform to the shape and dimensions of the interior of a man-entry sized pipe line. The adjustable form can be used to position a sheet of liner material immediately adjacent the inner sewer walls. An air cushion system is utilized to reduce friction and drag between the sheet of liner material and form so that the liner sheet can be easily adjusted prior to bonding to the inner walls of the pipe line.

RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. ProvisionalApplication No. 60/422,948, filed Oct. 30, 2003, which is herebyincorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] This invention relates generally to an apparatus and method forinstalling a liner within a pipeline, and more particularly, to anapparatus and method for installing a liner in man-entry sized pipessuch as underground sewer pipes and the like.

[0004] 2. Description of the Related Art

[0005] Sewer pipes are typically constructed of concrete and configuredto transport massive volumes of sewage on a daily basis. Most concretesewer pipes deteriorate over time due to repeated exposures to corrosivesewer gases such as hydrogen sulfide. Corrosive sewer gas can erode theinner walls of the sewer pipes and form cracks that would allow sewergas to escape and ground water to seep through. To address this problem,systems and methods have been developed to rehabilitate the older sewerpipes. One such method involves retrofitting the pipe with a liner onits inner surface. The liner is typically made of corrosion resistantmaterial such as polyethylene or polyvinylchloride (PVC). A commonlyused method involves applying an annular slipliner to the conduit byinserting a rigid PVC pipe into the bore of the conduit so as to providea corrosion resistant passageway. A cement grout is usually injectedinto the cavity between the pipe and the conduit to affix the pipe tothe conduit. However, the thickness of the pipe in conjunction with theannular gap created between the conduit and the pipe can reduce theeffective diameter of the sewer passageway, which in turns reduces theamount of sewage that can be transported.

[0006] An alternative pipe liner has been recently developed to addressthe shortcomings associated with the above-described annular slipliners.The new pipe liner is generally comprised of a flexible sheet ofmaterial such as PVC that conforms to the contours of the inner surfaceof the conduit. The flexible sheet liner is typically much thinner thanthe annular slipliners and thus does not noticeably reduce the diameterof the sewer passageway. However, the process of applying the sheetliner to the conduit can be labor intensive as it involves positioning arelatively large sheet of liner such as PVC adjacent the inside surfaceof the sewer pipe and then injecting grout between the liner and thesewer wall to secure the liner to the wall. It can be appreciated thatthe PVC sheet is typically very heavy and therefore difficult to placeand hold in position before grout is applied to bond the sheet to thepipe wall. Moreover, significant time and labor are often required tocarry the heavy roll of PVC material into a man-entry sized conduit,unroll the material, and then lift the material so that it is positionedadjacent the inside surface of the conduit before grout is applied.Presently, almost the entire sheet lining process is performed manuallyand the inventor is not aware of any equipment that has been developedto facilitate the placement of sheet liners inside sewer pipes becausethe process of retrofitting sewer pipes with liner sheets is relativelynew in itself.

[0007] Hence from the foregoing, it will be appreciated that there is aneed for an apparatus and method that will facilitate application of asheet liner inside a man-entry sized pipe line. To this end, this is aparticular need for an apparatus or process that reduces the amount oftime and labor required to apply a sheet liner to the inner walls ofsewer pipes.

SUMMARY OF THE INVENTION

[0008] In one aspect, the preferred embodiments of the present inventionprovides an apparatus for installing a sheet of pipe liner inside aman-entry sized pipe. The apparatus comprises a form having an exteriorsurface adapted to position the sheet of pipe liner adjacent the innerwalls of the pipe, wherein the exterior surface substantially conformsto the contours of the inner walls. The apparatus further comprises anair cushion system that reduces the friction between the sheet of pipeliner and the exterior surface of the form. In one embodiment, the aircushion system comprises a network of pipes adapted to transportpressurized air to a plurality of openings formed in the form.Preferably, the form can be extended and retracted both horizontally andvertically. In one embodiment, the form comprises an upper portion andside walls, wherein the side walls can be pivoted relative to the upperportions.

[0009] In another aspect, the preferred embodiments of the presentinvention provide an apparatus for installing a pipe liner inside asewage pipe having a first cross-sectional configuration. The apparatuscomprises a form having at least one movable surface which receives aflexible sheet of liner wherein the movable surface is movable between afirst position and a second position, wherein the movable surface in thesecond position is positioned substantially adjacent the inner wall ofthe sewage pipe with the liner positioned substantially adjacent theinner wall of the sewage pipe. The apparatus further comprises anadhesive injection system that injects an adhesive between the liner andthe inner wall of the sewage pipe to adhere the liner to the inner wallof the sewage pipe.

[0010] In one embodiment, the form comprises a plurality of curvedsections that collectively define the at least one movable surface.Preferably, the plurality of curved sections are hingeably attached toeach other so as to be able to expand outward so as to position the atleast one movable surface adjacent the inner walls of the sewage pipe.Preferably, the cross-sectional configuration of the form with the atleast one movable surface in the second position is substantially thesame as the cross-sectional configuration of the inner walls of thesewage pipe. In one embodiment, the cross-sectional configuration of theform with the at least one movable surface in the second positioncomprises a hemispherical shape. In another embodiment, the apparatusfurther comprises an air cushion system that reduces the frictionbetween the sheet of pipe liner and the movable surface of the form. Inyet another embodiment, the apparatus comprises an actuation system formoving the at least one movable surface between the first position andthe second position.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011]FIG. 1 schematically illustrates a pipe lining apparatus of onepreferred embodiment of the present invention;

[0012]FIG. 2 schematically illustrates the pipe lining apparatus of FIG.1 positioned inside a sewer line;

[0013]FIG. 3 schematically illustrates the pipe lining apparatus of FIG.1 having a sheet of lining material draped over the apparatus forinstallation.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0014] References will now be made to the drawings wherein like numeralsrefer to like parts throughout. FIG. 1 is a schematic illustration ofone preferred embodiment of a pipe lining apparatus 100 of the presentinvention. In the embodiment shown in FIG. 1, the pipe lining apparatus100 is designed to install liners in pipes that are semi-elliptical orhorseshoe shaped in cross section. These semi-elliptical pipes resemblean inverted “U” in cross section and are generally typical of oldersewer lines that were installed before 1960. Although the pipe liningapparatus shown in FIG. 1 is designed for rehabilitating older,semi-elliptical sewer pipes, it can be appreciated that the scope of thepresent invention is not limited to applying lining to these particularstyle of sewer pipes. Other embodiments of the invention are designed toinstall lining in pipes of different shapes and dimension, including butnot limited to, pipes with circular cross section.

[0015] As shown in FIG. 1, the pipe lining apparatus 100 generallycomprises a substantially arcuate form 102 that is configured tocorrespond to the general contour of a sewer pipe with a semi-ellipticalcross section. The form 102 comprises an elongate upper portion 104 anda plurality of sidewalls 106 a, 106 b extending downwardly from theupper portion 104 in a manner so as to form a semi-elliptical shell.Preferably, the form 102 is mounted on a carriage assembly 108 having aplurality of wheels 110 that permit rolling movement of the form 102.

[0016] In one embodiment, the form 102 is comprised of individual metalpanels that are connected together via a plurality of hinges 112. Thepanels are connected in a manner such that panels 114 comprising thesidewalls 106 a, 106 b can pivot relative to panels 116 comprising theupper portion 104 in a manner so as to permit the effective width 113 ofthe form 102 to expand or contract to conform to the cross-sectionalwidth of the sewer pipe. In one embodiment, the form 102 can be made toexpand or contract in cross-sectional width by operating a firstplurality of jacks 118 in a known manner. Preferably, the first jacks118 are adapted to retract or extend a plurality of telescopinghorizontal beams 120 extending between the two side walls 106 a, 106 b.In one embodiment, the jacks 118 are manually operated. In anotherembodiment, the jacks 118 can be operated by a hydraulic system suchthat each jack can be activated by a push button or other device.

[0017] When the telescoping horizontal beams 120 are retracted, thehinged side wall panels 114 are pulled toward the center of the form102, thereby decreasing cross-sectional width 113 of the form. Likewise,when the telescoping beams 120 are extended, the side wall panels 114are pushed outwardly away from the center of the form 102, therebyincreasing the cross-sectional width 113 of the form. Preferably, theside wall panels are in a retracted position when the apparatus is beingmoved into a sewer pipe. The side wall panels can be extended to conformto the dimension of the sewer pipe once when the form is positionedadjacent to the site where relining is to be performed. Moreover, theheight of the form 102 can also be adjusted by operating a secondplurality of jacks 122 which in turn will raise or lower a plurality ofvertical support beams 123 of the carriage 108. In one embodiment, thejacks 122 are manually operated. In another embodiment, the jacks 122are operated by a hydraulic system whereby each jack can be activated bya button, switch or other device.

[0018] Furthermore, as shown in FIG. 1, a plurality of openings 124 areformed in the upper portion 104 and side walls 106 a, 106 b of the form102. Preferably, each opening 124 is connected to a network of pipes 126lining the interior walls 128 of the form 102. As will be described ingreater detail below, pressurized air is preferably supplied by acompressor and transported by the network of pipes 126 to the openings124. Each opening 124 is configured to release a pre-determined amountof pressurized air, thereby creating an air cushion between the outersurface of the form 102 and the liner. This air cushion facilitatessliding movement and placement adjustment of the liner on the form. Inone embodiment, the openings are about 0.25 inches in diameter andadjacent openings are spaced about 12 inches apart. In anotherembodiment, the openings are placed in the upper half of the form wherefriction and drag force between the liner and the outer surface of theform are typically the greatest when the liner is slid across the form.

[0019] Advantageously, the network of pipes are formed adjacent theinternal walls of the form and configured to transport compressed air tothe openings in the form. The pipe lines lead to the openings 124 formedin the walls of the form. FIG. 1 also shows the hinges 112 connectingthe upper portion and side panels of the form and jacks 118 forextending and retracting the telescoping horizontal support beams.

[0020] In practice, the form 102 is rolled into a man-entry sized sewerpipe 200 and positioned adjacent an area where the liner is to beapplied as shown in FIG. 2. A roll of liner material 202, such ascorrosion resistant PVC, is positioned longitudinally on the upperportion 104 of the form 102. Preferably, the height of the form 102 isadjusted to accommodate the thickness of the roll 202 and still providesufficient headroom for the roll to be moved and adjusted on the form102. Moreover, the width of the form 102 is also preferably adjusted sothat operators can stand next to the side of the form 102 to properlyposition the liner.

[0021] In one embodiment, pressurized air supplied by a compressor (notshown) and transported through the network of pipes 126 inside the form102 is released through the openings 124 so as to form an air cushionadjacent the outer surface 125 of the form 102. Advantageously, the aircushion reduces the drag force between the liner 202 and the outersurface 125 of the form when the roll 202 is being moved or adjustedinto position. Once the roll of liner material 202 is properlypositioned on the upper surface 104 of the form, the liner 202 isunrolled and allowed to drape over the form 102 as shown in FIG. 3.Advantageously, the air cushion provides some lift for the liner 202 andreduces drag so as to reduce the force needed to pull the liner acrossthe form 102.

[0022] Once the sheet of liner 202 is properly draped over the form 102,the form 102 can be raised and expanded to position the linerimmediately adjacent the internal walls of the sewer pipe 200. The form102 can be extended vertically by activating the second plurality ofjacks 122 which are adapted to raise the vertical support beams 123 ofthe carriage 108. Similarly, the form 102 can be extended horizontallyby activating the first plurality of jacks 118 which are adapted toextend the telescoping horizontal support beams 120 of the carriage 108.As the horizontal support beams 120 telescope outwardly, the hinged sidepanels 106 a, 106 b of the form are pushed toward the inner side wallsof the sewer pipe.

[0023] When the liner is positioned immediately adjacent the inner wallsof the sewer pipe, grout is applied to the space between the liner andthe inner walls to secure the liner to the walls. In one embodiment,grout is injected through openings 204 formed in a bulkhead section 206of the apparatus 100 and into a cavity 210 between the upper surface ofthe liner 208 and portions of the inner walls of the sewer pipe 200.Preferably, the bulkhead section 206 comprises a substantially planarstrip of metal or other suitable material that extends outwardly fromthe perimeter of the form 102 in a direction substantially perpendicularfrom the sidewalls of the sewer pipe 200. The bulkhead section 206 isadapted to curb the flow of grout from seeping out from the cavity 210between the inner sewer walls and the liner.

[0024] After the grout sets and firmly bonds the liner 202 to the innersewer walls 210, the form 102 can be retracted in height and width byactivating the first and second plurality of jacks 118, 122. Onceretracted, the form 102 can be easily rolled to another section of thesewer pipe that require lining. In one embodiment, the wheels 110located near the middle section of the carriage 108 can be pivotedupwardly in a manner such that the rolling surface of each wheel 110contacts the sidewalls of the sewer pipe as the apparatus is moved alongthe sewer pipe. In one embodiment, the wheels can be manually pivoted ormoved using a motorized system.

[0025] Advantageously, the preferred embodiments of the presentinvention provide a pipe lining apparatus that reduces the amount oftime and labor needed to retrofit a man-entry sized sewer line. Withoutrequiring extensive manual labor, the apparatus can be positioned insidethe sewer pipe, adapted to conform to the dimensions of the pipe andposition a layer of liner sheet adjacent the inner walls of the pipe.Moreover, the apparatus utilizes a unique air cushion system to reducefriction and drag so that the liner material can be easily moved andadjusted prior to lining the pipe.

[0026] Although the foregoing description of the preferred embodiment ofthe present invention has shown, described and pointed out thefundamental novel features of the invention, it will be understood thatvarious omissions, substitutions, and changes in the form of the detailof the apparatus as illustrated as well as the uses thereof, may be madeby those skilled in the art, without departing from the spirit of theinvention. Consequently, the scope of the invention should not belimited to the foregoing discussions.

What is claimed is:
 1. An apparatus for installing a sheet of pipe linerinside a man-entry sized pipe, comprising: a form having an exteriorsurface adapted to position the sheet of pipe liner adjacent the innerwalls of the pipe, wherein the exterior surface substantially conformsto the contours of the inner walls; an air cushion system that reducesthe friction between the sheet of pipe liner and the exterior surface ofthe form.
 2. The apparatus of claim 1, wherein the air cushion systemcomprises a network of pipes adapted to transport pressurized air to aplurality of openings formed in the form.
 3. The apparatus of claim 1,wherein the form can be extended and retracted in a horizontaldirection.
 4. The apparatus of claim 1, wherein the form can be extendedor retracted in a vertical direction.
 5. The apparatus of claim 1,wherein the form comprises an upper portion and side walls, wherein theside walls can be pivoted relative to the upper portion.
 6. An apparatusfor installing a pipe liner inside a sewage pipe having a firstcross-sectional configuration, the apparatus comprising: a form havingat least one movable surface which receives a flexible sheet of linerwherein the movable surface is movable between a first position andsecond position, wherein the movable surface in the second position ispositioned substantially adjacent the inner wall of the sewage pipe withthe liner positioned substantially adjacent the inner wall of the sewagepipe; an adhesive injection system that injects an adhesive between theliner and the inner wall of the sewage pipe to adhere the liner to theinner wall of the sewage pipe.
 7. The apparatus of claim 6, wherein theform comprises a plurality of curved sections that collectively definethe at least one movable surface.
 8. The apparatus of claim 7, whereinthe plurality of curved sections are hingeably attached to each other soas to be able to expand outward so as to position the at least onemovable surface adjacent the inner walls of the sewage pipe.
 9. Theapparatus of claim 8, wherein the cross-sectional configuration of theform with the at least one movable surface in the second position issubstantially the same as the cross-sectional configuration of the innerwalls of the sewage pipe.
 10. The apparatus of claim 9, wherein thecross-sectional configuration of the form with the at least one movablesurface in the second position comprises a hemispherical shape.
 11. Theapparatus of claim 6, further comprising an air cushion system thatreduces the friction between the sheet of pipe liner and the movablesurface of the form.
 12. The apparatus of claim 6, further comprising anactuation system for moving the at least one movable surface between thefirst position and the second position.